/Engine/Plugins/FX/Niagara/Source/Niagara/Public/NiagaraComponent.h
Gets the desired age of the System instance. This is only relevant when using the DesiredAge age update mode.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category=Niagara, Meta=(DisplayName="Get Desired Age")) float GetDesiredAge() const